Vented explosion-proof lighting unit



Sept. l5, 1953 c. H. BlsSELl.

VENTED EXPLOSION-PROOF' LIGHTING UNIT Filed April 1o Patented Sept. 15,1953 VENTED EXPLOSION-PROOF LIGHTING UNIT Carl H. Bissell, Syracuse, N.Y., assgnor to Crouse-Hinds Company, Syracuse, N. Y., a corporation ofNew York Application April 10, 1950, Serial No. 154,968

1 Claim. 'E

This invention relates to explosion proof lighting units and has for anobject an explosion proof lighting unit embodying a structure whereinthe lamp chamber of the unit is provided with a large venting area, orareas, of the llame arresting type, whereby there is developedsubstantially no pressure within the tting in the event inflammablegases Within the lamp chamber are ignited, the structure beingparticularly economn ical to manufacture and assemble.

The invention consists in the novel features and in the combinations andconstructions hereinafter set forth and claimed.

In describing this invention, reference is had to the accompanyingdrawings in which like characters designate corresponding parts in allthe views.

In the drawings- Figure 1 is a vertical sectional View of a lightingunit embodying my invention.

Figure 2 is a View taken on line 2 2, Figure 1.

The body of the fitting consists of a cylindrical portion I having adepending annular flange I I threaded internally and externally. A lampreceptacle I2 is threaded into the flange II, and a supporting member I3is threaded on the exterior of the flange. The supporting member I3 isof annular formation having a plurality of circumferentially spacedareas of slightly reduced thickness in which there are mounted a seriesof porous flame arresting vents I4. The vents I4 may be in the form ofcircular disks formed of sintered metal with their peripheral marginalportions embedded in the supporting member. A supporting member of thisstructure may be produced by arranging the sintered metal disks in amold in which the supporting member is cast.

The peripheral edge of the supporting member is provided with threads toreceive the internally threaded flange I5 of a globe ring I6. The ringI6 has a depending flange Il threaded internally to receive an annularnut I8 coacting with a radial flange I9 of the glass globe 20, todetachably position the flange of the globe in ame tight relationagainst the ring I5, as illustrated in Figure 1.

The supporting member I3 may be secured on the flange Il of the bodyagainst displacement by means of a set screw 2I, and the globe ring I5may be likewise secured in place by a set screw 22 threaded into adepending flange 24 of a canopy 25 carried by the body and overhangingthe support I3.

With this arrangement, the receptacle I2, support I3 and globe 20 form aflame tight compartment for the lamp 26.

Due to the annular formation of the supporting member, several of thevents I4 can be provided to establish a large venting arrangement whichis eifective to quickly permit exploded gases within the lamp chamber tobe vented therefrom and accordingly minimize the possibility of anypressure being built up Within the fitting by the explosion.

The canopy 25 overhanging the supporting member I3 and encircling theperiphery thereof effectively prevents foreign material from fallingonto the vent members I4. However, the supporting member I3 can bequickly and conveniently removed from the unit for cleaning in the eventit should become necessary to do so. Inasmuch as the venting members I4constitute part of the supporting member I3, it is impossible toassemble the unit without the supporting member in proper position. Thisavoids the possibility of a workman dis-assembling the unit for anyreason and re-assembling it Without the flame arresting vent members I4being put in operative position.

What I claim is:

An explosion proof lighting unit comprising a cylindrical body having anend portion threaded externally and internally, a lamp receptaclethreaded into the threaded end of the body, a flat annular supportingmember threaded on the body and extending radially therefrom, theperiphery of said supporting member being threaded eX- ternally, a globesupporting ring threaded on the periphery of said supporting member, aglobe detachably secured to said ring in ame tight relation thereto,said body being formed with an integral canopy portion extendingradially over said supporting member and having a depending flangeencircling said globe ring in spaced relation thereto, said supportingmember being formed with a plurality of porous flame arresting ventsformed of sintered material.

CARL I-I. BISSELL.

References Cited in the le of this patent UNITED STATES PATENTS NumberName Date 1,224,162 Griswold May 1, 1917 2,050,839 Hastings Aug. 11,1936 2,530,135 Tornblom Nov. 14, 1950

